Launched in 2006 by Tony Blair to "make life hell" for organised crime, the Serious Organised Crime Agency (Soca) took over the functions of a number of agencies, including the National Crime Squad (NCS).

It has faced criticism from police for making little impact, despite having more than 4,000 officers and an annual budget of £400m, while others suggested it behaved like a secret intelligence agency and concentrated too much on international issues.

Soca's director general, Bill Hughes, formerly of the NCS, can designate his officers with the powers of a police constable, a customs officer, or an immigration officer. The new chairman is to be Sir Ian Andrews, a career civil servant with no experience of policing.